An experimental demonstration of the memristor test

TL;DR

This paper experimentally tests a recent memristor identification method on a device claimed to be a memristor, and finds it is actually an inductor with memory, questioning the existence of ideal memristors.

Contribution

It applies a recent unambiguous memristor test to a claimed device, providing clear evidence that it is not a true memristor, thus challenging prior claims.

Findings

The device tested is an inductor with memory, not a memristor.

The test conclusively distinguishes memristors from other devices.

Ideal memristors may not exist in nature or be easily fabricated.

Abstract

A simple and unambiguous test has been recently suggested [J. Phys. D: Applied Physics, 52, 01LT01 (2018)] to check experimentally if a resistor with memory is indeed a memristor, namely a resistor whose resistance depends only on the charge that flows through it, or on the history of the voltage across it. However, although such a test would represent the litmus test for claims about memristors (in the ideal sense), it has yet to be applied widely to actual physical devices. In this paper, we experimentally apply it to a current-carrying wire interacting with a magnetic core, which was recently claimed to be a memristor (so-called `$\Phi$ memristor') [J. Appl. Phys. 125, 054504 (2019)]. The results of our experiment demonstrate unambiguously that this `$\Phi$ memristor' is not a memristor: it is simply an inductor with memory. This demonstration casts further doubts that ideal memristors do actually exist in nature or may be easily created in the lab.